Bio:
Mother Crane is a mystic leader of the city of Kun-Zi. Kun-Zi is one of the seven heavily cities in the Iron Fist mythos. The Seven Heavily Cities get together to fight in a martial arts tournament. The main warrior of the city of Kun Lun the Iron Fist refuses to take part in the tournament. This Iron Fist by the name of Orson Randall earned the wrath of Mother Crane. The tournament was an important event of the Heavenly Cities and very important to Mother Crane. Randall was stripped of his title after killing one of the other immortal weapons as he escaped.

Crane Mother sent Davos the Steel Serpent to exact revenge on Orson. Davos was provided with numerous female warriors called the Daughter Cranes. These women could sacrifice themselves and give their Chi to another warrior giving them great powers. Steel Serpent used these Crane Daughters to fill himself with powers to fill himself full of power. He began hunting both Orson Randall and the new Iron Fist Danny Rand. Orson Randall sacrifices himself and gives Danny all of his Chi, this enough for Danny to defeat Davos and the Crane Daughters.

Crane Mother then is shown as presiding over the Tournament of the Heavenly Cities.

Powers:
Master of Martial arts

Mystical powers

Can create Crane Daughters who are powerful female martial artists who can sacrifice themselves to give another person their power or Chi.

MCU - Madame Gao

The character Madame Gao in the Netflix Daredevil series. Madame Gao is shown running a heroine distribution group and is connected to Wilson Fisk's criminal. The heroine she is selling is marked with the same symbol as Steel Serpent and is called "Still Serpent". Though appearing to be an old woman she is able to bring down Daredevil with a single well placed strike.
When she leaves NYC she says she is going home, when asked if that is China she replies that her home is considerably farther away. This is likely referring to the heavily city of Kun-Zi.

When added together, the reference to a Home farther than China, super strength and the Steel Serpent symbol all point to Madame Gao being Crane Mother.

Iron Fist Season 1:

Madame Gao voice can be heard in the Iron Fist trailer telling Meachum that Danny Rand should not be in the city. It also seems that Rand corp has become embroiled with Gao criminal empire in some way. This will likely lead Gao to being a major villain in Iron Fist season 1.

It would not surprise me if more about Gao's true identity come out. The Steel Serpent symbol also appears in the trailer. Being that Gao already used the Steel Serpent symbol on the drugs being shipped from her organization it seems like a certainty that Gao and Steel Serpent will be connected.